package com.gym.core.hash;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public interface Hashing {

    public static final Hashing MURMUR_HASH = new MurmurHash();

    public ThreadLocal<MessageDigest> md5Holder = new ThreadLocal<MessageDigest>();

    public static final Hashing MD5 = new Hashing() {

        public long hash(String key) {
            return hash(SafeEncoder.encode(key));
        }

        public long hash(byte[] key) {
            try {
                if (md5Holder.get() == null) {
                    md5Holder.set(MessageDigest.getInstance("MD5"));
                }
            } catch (NoSuchAlgorithmException e) {
                throw new IllegalStateException("++++ no md5 algorythm found");
            }
            MessageDigest md5 = md5Holder.get();

            md5.reset();
            md5.update(key);
            byte[] bKey = md5.digest();
            long res = ((long) (bKey[3] & 0xFF) << 24) | ((long) (bKey[2] & 0xFF) << 16)
                    | ((long) (bKey[1] & 0xFF) << 8) | (long) (bKey[0] & 0xFF);
            return res;
        }
    };

    public long hash(String key);

    public long hash(byte[] key);
    
    
    
    public static class SafeEncoder{

        public static byte[] encode(final String str) {
            try {
                return str.getBytes("UTF-8");
            } catch (UnsupportedEncodingException e) {
//                e.printStackTrace();
            }
            return new byte[0];
        }

        public static String encode(final byte[] data) {
            try {
                return new String(data, "UTF-8");
            } catch (UnsupportedEncodingException e) {
//                e.printStackTrace();
            }
            return "";
        }
}
}
